Author Topic: Motorola Identification - Quality??  (Read 7750 times)

fastdog

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Re: Motorola Identification - Quality??
« Reply #15 on: June 24, 2015, 09:18:45 PM »
Thanks Pat, just needed some reassuring!!!
Tim

fastdog

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Re: Motorola Identification - Quality??
« Reply #16 on: June 26, 2015, 08:47:24 PM »
OK, picked up this beautiful unit and am finding that the right channel doesn't work, neither the inside speaker nor the external right speaker that it came with. I've tested the external with another stereo and it is in working order so the problem comes from within the unit. What should I check first???
Tim

624Magnificent

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Re: Motorola Identification - Quality??
« Reply #17 on: June 26, 2015, 08:59:32 PM »
First question. Has the amp been serviced?? New capacitors, switches cleaned etc. If not that's a good place to start. Don't run it if you think the capacitors are old until it's been serviced. You can do damage!!

Assuming the amp is ok. Simple things to look at.

Does it have a knob / switch for choosing "internal" vs "external" speakers? If the switch contacts are dirty you can lose a channel. Do you have any De-Oxit contact cleaner??

Another quick and easy check is to see if the speaker drivers are good. Take a multimeter and check each driver for resistance. You should get a reading of say 4 to 8 ohms depending on whether it's a woofer or tweeter. Once you know the drivers are ok you can work backwards. Check wires, connectors etc.

If you rule out the easy stuff then you can go after the amp.
Tom

fastdog

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Re: Motorola Identification - Quality??
« Reply #18 on: June 26, 2015, 09:41:59 PM »
Thanks so much 624!!!! 
No, it hasn't been serviced, the guy I got it from had it fired up when I got there. No,  it doesn't have the switch for external, internal let keep our Maggie's do. Everything is in pristine condition except for that right channel.  :-[
Tim

fastdog

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Re: Motorola Identification - Quality??
« Reply #19 on: June 26, 2015, 09:51:20 PM »
Also, this unit has an external speaker that connects via an RCA  plug into the back of the unit and it's not playing as well.
Tim

624Magnificent

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Re: Motorola Identification - Quality??
« Reply #20 on: June 27, 2015, 07:12:48 AM »
Hmmm sounds like it could be a bad capacitor or resistor in the amp. You could spend time going through each component with a multimeter to find the offending gremlin but with these 60 year old amps you can solve a lot of issues by starting with replacement of all the electrolytic, paper and wax caps. If you are handy with a soldering iron and have a healthy respect for electricity you can do it yourself, many here have. If that's not your cup of tea there's usually someone in your area that does that type of work. You might try hooking up with an antique radio club.
Tom

fastdog

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Re: Motorola Identification - Quality??
« Reply #21 on: June 28, 2015, 06:19:57 PM »
Pulled the amp and took it to a local guy who does this.... We'll see the outcome. Thanks guys!!
Tim

fastdog

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Re: Motorola Identification - Quality??
« Reply #22 on: July 04, 2015, 06:11:33 PM »
Well, he called me a couple of days ago and said the amp was fine... Some tubes tested weak but no reason to not hear the right channel. Asked me to bring in the tuner section of the piece... Needless to say it was easier to load up the whole "250 lb" lol console and take it. Haven't heard from him in a few days and wondering what the  assessment could be now that the amp has been ruled out??
Tim

fastdog

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Re: Motorola Identification - Quality??
« Reply #23 on: July 09, 2015, 09:05:56 AM »
Help from anyone who knows this unit?!
Motorola SK18M...
There is a setting on the dial that reads "RIAA"... am I understanding that ONLY when playing a record with the Compensater set at" RIAA " will this be stereo and sound will come from both left and right?  I believe that it's a mono system during radio play but shouldn't I be hearing mono sound from all of the speakers or just the left channel?  The guy doing the assessment for me seems to think nothing is wrong with it. Any help appreciated!!
Tim

Consoleman

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Re: Motorola Identification - Quality??
« Reply #24 on: July 09, 2015, 11:09:49 AM »
Help from anyone who knows this unit?!
Motorola SK18M...
There is a setting on the dial that reads "RIAA"... am I understanding that ONLY when playing a record with the Compensater set at" RIAA " will this be stereo and sound will come from both left and right?  I believe that it's a mono system during radio play but shouldn't I be hearing mono sound from all of the speakers or just the left channel?  The guy doing the assessment for me seems to think nothing is wrong with it. Any help appreciated!!

The equalization should have nothing to do with mono/stereo.
Mark

fastdog

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Re: Motorola Identification - Quality??
« Reply #25 on: July 09, 2015, 11:23:33 AM »
Thanks Mark, that's what I thought. I  should be hearing sound from both of these channels. Beginning to think that that "Compensator" switch is the problem.
Tim

624Magnificent

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Re: Motorola Identification - Quality??
« Reply #26 on: July 09, 2015, 02:33:01 PM »
Did your guy clean all the knobs / switches with contact cleaner? That's often a place to start when a channel is intermittent.
Tom

fastdog

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Re: Motorola Identification - Quality??
« Reply #27 on: July 09, 2015, 02:49:01 PM »
He's in the business for 40+ years so I'm hoping he knows that Tom. Haven't heard back from him yet.
Tim

fastdog

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Re: Motorola Identification - Quality??
« Reply #28 on: July 09, 2015, 05:36:02 PM »
Here's the new rundown on this piece... AM working, FM not. Still nothing coming from right channel. He said that one of the 4 6BQ5's caps red after about 10 minutes of it being on. I don't know this unit as some of you might so I'm throwing it out for some feedback... The cabinet is in amazing condition, tuner and record changer are next to perfect. A ball park price he gave me to get her going was "probably near $250-300 without getting into it and tearing it down yet idea. Is this one going to be worth all of that?  And yes, I got it for a steal at $75. All comments welcome.  ???
Tim

Pat L

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Re: Motorola Identification - Quality??
« Reply #29 on: July 09, 2015, 06:19:33 PM »
With a unit like this it certain things must be done to bring it back to full operational status. There is no traditional troubleshooting needed as it's not broke. It's more like a beautiful old flashlight with 20 year old batteries in it. Of course it doesn't work, but it's certainly not broke.


 The capacitors in this unit need to be changed, every switch must be cleaned, the tube sockets must all be cleaned. The record changer will require disassembly and cleaning and fresh lubrication. It will probably need a new cartridge and needle, it may also need a new idler wheel. All the light bulbs should be changed, and the tubes should be tested and changed as required.


You have a beautiful unit that cost the same as a night out at the movies. Perhaps you could consider doing some of these things yourself. A nice soldering station costs less than the repairman quoted you. The new capacitors are not expensive at all. The most expensive parts will be for the record player. You might spend $50 to $75 on it.